greenking

Hi all Experts,
I am hoping someone can tell me whta turbo is in a UK95 imprezza and is there are anything I can do to check to see if there is any damage etc...
I am hoping of up-grading the turbo but I am looking for better response and better pulling power. I will be mainly using the car on the road so do not want 'a bigger turbo', I was mainly thinking of the other turbos used on possibly the sti's or the newer UK cars??
Also what is the boost limited to on my car??
Regards
G.

Karlos

Greenking,

Im in the same boat, as I drive a MY96 UK Turbo with a tired blower, mainly due to the mileage. I have managed to deduce from members of the BBS that my car has the TD05 turbo, which is rumoured to be better than the TD04 fitted to later cars. No one has been forthcoming however with what the options are with regards replacing/recon'ing or hybridizing (I know it's not a real word!) this turbo.

Hopefully we'll both get the answers were looking for!

Karlos

TonyBurns

iTrader: (3)

Greenking,
you definately dont want to fit an STI or WRX turbo to your car as they are larger and more laggy. Some say that the older turbos are better than the newer ones, have a MY00 turbo myself and dont see what they are getting at???? no lag here!!
If you want more power then an exaust and filter seem to be the best way of going about it, get those 'orrible little gasses out of there quicker and you should feel more response, or if you can afford it go for a chip, just make sure your insurance co is 'chip' friendly thou or you could have a big bill on your hands!!
Oh and its Impreza and not Imprezza!! ta

Tony

greenking

Thanks Tony,
I will try and spell my words better!!!!
At the moment i have upgraded all the items you have said and possible more.
Karlos,
Maybe you can e-mail me what you have on your car??
Regards
G.

DJB

Having owned a MY95 and now a MY98, I can assure you that the larger turbo (MY95) is far more laggy.

I understand that to make up for the smaller turbo in MY97 onwards, the compression ratio was increased compared with before so you probably could not fit a post MY97 turbo to the older models. If you were to stick with the OEM turbo, I suppose that, if you can prevent detting, there are greater gains to be had from increasing the boost on the older larger turbo cars.

D.

Bob Rawle

The TD05H is as big or bigger than the largest VF used on the WRX and is definately bigger than any of the STi turbo's. Fitting one of those is going backwards. Contact Turbo Dynamics and discuss your options with them. Oh its also a very robust turbo, much more so than the VF series as its a sleeve bearing unit not a ball race.

logiclee

Bob is correct,

Pre 97 MY cars had "probably" the biggest Turbo fitted to standard Impreza's. Changing to later turbo's is far from straight forward, as well as the turbo you'll be looking at intercooler, all intake piping and downpipe and thats before you start considering compression ratio's.

Speak to a turbo specialist but you'll be sticking with a modded TD05 I think.

Lee

greenking

Thank you all for the info!
I will phone up turbo dy.
I was also wondering if any of you guys/girls know what boost the car will cut at??
I have been told at about 1.2 bar??
Is this correct?

pat

greenking,

The MHI TD05H as fitted to your car *IS* the largest turbo ever fitted by Subaru to a production Impreza, making it even bigger than the often over-rated VF22, and more robust to boot. The only "problem" with it is that its spool up is limited by the sleve bearing and its intake is seriously imeded by the 90 degree bend on the front.

The latter "problem" can be fixed by Owen Developments, they'll machine your compressor cover to a straight entry, just like all the later turbos, this makes it a bit of a monster. In stock form it will run 1.6 bar all day every day all the way to the redline without breaking a sweat. With this mod the partial vacuum at the entry is reduced allowing greater flow and pressure ratio. Should have some results later this week on the performance of an MY97 engine on this modded TD05.

The problem with this is that the intake pipework WILL NOT clear your manifold, so you will need an MY97 or MY98 intake manifold, and power steering reservoir.... the rest shoudln't be too difficult to swap, only the TPS sensor needs a new connector splicing into the loom...

All UK cars from '91 to '00 run an MHI TD04 turbo which is a tiny turbo in comparison. Yo'll get much better bottom end pick-up with one of these, but you'll lose top end. In any case, this also needs a new manifold.

If your turbo is just "tired" and the shaft has not been damaged then Owen will rebuild it for the princely sum of UKP 150 plus VAT; that includes new bearings, seals, etc, and it will come back looking good as new :-)

If you want more details as to pricing for the MY97 manifold swap, give Pete @ Scoobysport a call, we've done a few now, got it down to a fine art :-)

Hope this helps,

Pat.

greenking

Hi all,
I am now a bit confused.
Everyone says I have a TD05 on my car (95MY uk turbo impreza) but now pat is saying that UK cars from 91-00 run a TD04?? I am asuming that 91 is really a 97???
Please advise.
Pat, if this is correct then what do I need to change if I want Owen/Pete to 'sort' out the turbo.
How long will it take to do this mod??
NOONE HAS TOLD ME ABOUT WHAT BOOST LIMIT IS SET ON THE 95MY MODELS??
Thanks again.
I will need to think this over, as it is getting a bit too technical.
Pat, maybe you can e-mail me off line about ALL the changes I will need to do and more information too, like performance, any changes that need to be taken care off.
Will be waiting for your answers impatently.
Regards
G.

logiclee

I think Pat meant 97 not 91.

Standard turbo pressure for the TD05 was 11.9psi . Later turbos run higher boost but the bigger the Turbo the less boost you need for the same power.

The TD05 will run much higher boost without turbo damage. Modifying the intake for a straight input will make it more efficient.

If you up the boost you will need an ECU upgrade so the fueling and ignition can be optimized to prevent pre detonation and a blown engine. Its not a good idea to just up the boost on an Impreza.

Lee

Blackscooby

When I get chance I'll look to see which version of turbo my UK94 has. When I blow a piston due to excessive boost we changed the turbo from the original laggy TD005 to a smaller one which is less laggy. (or it feels that way).

Its very noisy when scolling up, but it scrolls up nicely. You can hear it scrolling up and down ~ a sound I love to be honest.

I'm sure a WRX turbo was fitted ~ but I'll check.

Mark.

Karlos

Greenking,

I am in discussions with Universal-turbos at the moment (www.universal-turbos.com) regarding hybrid/reconditioning work on my TD05 (replacing seal, 360 degree thrust bearings, etc). Apparently, this turbo is the strongest of all turbo's fitted to Scooby's and is good for around 300bhp!!! However, it does take longer to spin up then the TD04 fitted to '97 on cars (just confirming what others have said, and from experience as my boss has a MY99!) As far as mods to my car already, I found, as someone has already said, changing the exhaust and fitting an induction kit improved the car immensly... do this first, unless of course your turbo is a little tired like mine.....

Hope this advice helps.

Karlos

greenking

Hi Karlos,
I have already done the exhaust and air filter.Looking at trying to improve the turbo or get it 'shipshape' before I do major mods.
Also will be looking at trying to improve the reliability of the bottom end in the near future.
Any info??
Regards
G.

pat

greenking,

Sorry about the confusion, a simple typo and all hell breaks loose, eh? LOL. What I meant to type was '97 - '00 *NOT* '91 - '00 :-) You are quite right, it 97 not 91 :-)

If you want to swap the turbo intake piping then you will need the following:

MY97-MY98 intake manifold, injector rails, throtttle body, throttle position sensor, throttle position sensor plug, breather pipework, intake "trumpet" that goes onto the turbo, *possibly* water cross-pipe and MY97 water cross-pipe to bulkhead hose, modified TD05H turbo, power steering reservoir, rubber hose from trumpet to airbox / AFM unit, good co=ne filter (too much of a pig to fit the later airbox to the earlier AFM unit), throttle cable (or custom bracket to hold original), possibly new water reservoir.

You can re-use your original injectors, they'll just fit into the new rail, but the old rails do not fit the new manifold.

Start by unplugging the existing loom from all the accessible sensors and coil packs, and remove as much of the breather / water pipework as possible. Also disconnect the fuel supply, return and vent pipes. You'll also want to remove the power steering supply and return lines from the manifold, this will require their removal from the pump.

Next disconnect the loom connectors from their parterns on the car loom so the engine loom will come away with the manifold. Undo the bolts that hold the manifold on and pull it off the manifold, disconnecting any remaining connectors or pipework in the process. You'll now have a "bar" engine top, be careful not to contaminate the intake ports! You may want to swap over the water cross-pipe now, apparently the original would interfere with the new fuel rails (I don't run them so cannot confirm that it is definitely necessary to change it). Unclip the wiring loom and then attach it to your new manifold, remembering what plugs in where :-) It may need a bit of stretching to fit the new manifold! If you don't have new injectors, swap them over now as well.

Unbolt the power steering reservoir (or whole pump) and fit the new one with the sloping side. Assuming the turbo has already been modded, fit this now, it's easier with the manifold off! In fact, the turbo will not fit with the new manifold and old 90 degree bend, so you must have this changed first anyway....

Refit the manifold, making sure not the connect water and breather pipes incorrectly, that gets expensive! The pipework that came with the new manifold should line up perfectly with the old locations if you have the new cross-pipe, if you do not, you may need a longer hose for the ISC and throttle body heater pipe.

Bolt the manifold down so it's "safe" (ie intake ports are protected again. Plug the loom back into the car loom. The remaining connectors may now be plugged into the sensors on the car (cam, crank, oil pressure, knock, water temp for dash adn ECU, coil packs, power steering pressure etc etc). The intake trumpet should just line up with the turbo but may be a bit "reluctant" to go on; just undo the bolt at the front of the manifold that secures it to the manifold, then it may be twisted a bit to persuade it :-).

With the manifold back on, a few water pipes will have nowhere to go; these go onto the water reservoir. If you don't want a new one (expensive) file down the sloping edge at next to the rear mounting hole so as to allow the old tank to be bolted to the new manifold then secure it on the rear bolt only (spacing is different!) It may be useful to re-fit the power steering pipework before finally mounting this reservoir; this may take some "persuasion".

With all the water and breather pipes back where they should be, reconnect the fuel lines. You'll also need to fit the rubber hose that goes between the trumpet and the AFM, then fix your new cone filter (this should be for an MY97 car, it'll need to be mounted in the newer orientation).

The throttle position sensor will not plug in since the new one has only 3 pins whereas the old one has 4. Can't remember the way the new one needs to be spliced in off the top of my head, but I can find out when I get my car back :-)

The ISC should just plug in, and should all of the other stuff, but maybe at a stretch. If I haven't forgotten anything then it should be ready to go....

Hope this helps,

Pat.

greenking

Hi Pat,
Now that I have seen your posting,you are scaring me!!!!
One question comes to mind, is where do I get all this stuff????
And I can safely say that it is not a one day job!!
No wonder people just buy another turbo/turbine.
I am thinking of that now!!
I will need to compare the costs etc......
I assume you have done this before??
How long did it take and if you can give me an approx. cost
Regards
G.

Karlos

Pat,

I'm with Greenking on this one. Your blinding us both a bit with the science of it all. I don't know about Greenking, but I.T. is my bag. Give me some spanners and put me under a bonnet and you might as well saw my arms off for all the use I am!!!

What does all this work actually give you compared with just replacing the TD05 with a hybrid?

Karlos

greenking

Hi all,
Ok the mods on my car are as follows:
1)HKS super drag exhaust from turbo
2)HKS induction kit.
3)HKS SQV
4)boost controller etc.

As you can see I have improved the air intake, the exhaust, etc..
Did have a magnex but was not what I expected.
Like you say.
You pay your money......

pat

Hi greenking!

scaring you? You should see what I had to get the Pectel T6 Motorsport ECU to work! :-)

The stuff, well, you have a choice. Either arrange for the upgrade with an establishment such as Scoobysport and let them take the strain, or get your blower ready to ring around a few breakers :-) I'de recommend Grade A, they have loadsa scooby stuff in stock.... should get what you need...

It sounds like a lot of work on paper, but it shouldn't take a day, no, but I'de allocate at least an afternoon or a morning to it, perhaps slightly longer.

Your point about another blower is missing one vital element. Any such replacement blower would also need the 90 degree elbow, or be mounted at about 45 degrees to the normal direction in order to clear the manifold. It *is* possible to weld a 90 degree bend onto the front of a turbo, but I prefer a straight entry path. You'de be amazed at what difference something as "insignificant" as a minor step in the tubing can do... up to 20% impact on flow rate, so just imagine what a great 90 degree bend will do!

You are correct, I have indeed swapped manifolds, on more occasions than I care to remember It's not that bad once you get the hang of it.... but I must admit I've not done one in the car yet. Still shouldn't be too bad.

Approximate time... errr, loads of hours, but I was learning at the time :-) The last one I did in the space of about 1-2 hours. Cost, dunno really, never totted it up, and there was a bit of a barter arrangement as well, so impossible to say. Give Pete a call, he's done these before and should be able to advise on a price.

Karlos,

science, you really do not want to go into fluid dynamics... that is scary science, actually explaining why it works better / preicting flow characteristics (is it laminar, turbulent ? combination etc)... funny how most Scooby owners are in IT I'm no exception, but I do like to dabble with engines.

I'm an engineer at heart, whether that be mechanical, electrical, software, chemical matters not. I like to try to understand how and why things do (or do not) work the way they do, then use that to "improve" upon the existing design, given the greater degree of freedom an end user has, as compared to a major manufacturer which must address all areas (including emissions etc). I'm not too bad with a spanner or wrench, but I won't claim to be anything other than an enthusiast.

Results are as yet unknown. I did get sensible boost at 2000 RPM out of a TD05, but I suspect that was more to do with my ignition timing being too retarded than the better breathing.

As for a hybrid, what do you suppose that is going to achieve, and at what expense? As I see it, the major problem with the existing design is the bend, any turbo which uses the same design but a different impeller will be subject to the same restrictions. In order to get round these, one either has to allow air under the inlet manifold straight into the turbo, or the turbo must be rotated about 45 degrees so that the intake comes from the driver's side wheel arch area directly into the turbo. This needs a new downpipe, up-pipe and a more drastic bend at the turbo outlet to get air into the stock intercooler.

The "perfect" orientation has the intercooler moved to the front of the car, the turbo entry pointing skywards, the outlet pointing under the intake manifold, the manifold reversed. Air comes in the scoop into an airbox which goes onto the turbo. Air exits directly under the intake manifold, no bends. Air goes into the intercooler and back out, direct to the throttle body (which is now facing forward not back). Very short pipework, low additional lag, nice cool charge, good flow....

Cheers,

Pat.

greenking

Hi Pat,
Thanks for explaining all that.
The front mounted I/C and Oil cooler were one of my future mods.
I am asumming that I would have to do the manifold conversion BEFORE anything else as the outlets will be all different??!!
Please could you tell me if I am right.
As I will be takig the engine apart I will be also best to upgrade the rods, cams etc for the bottom end??!!
Please advise Pat.
Regards
G.